Multiple differential



Nov. 3, 1942. B, Q, JONES 2,300,424

MULTIPLE DIFFERENTIAL ,Filed Sept. l1, 1941 to a wheel when the powerthereof fails.

Patented Nov. 3, 1942 I UNT MULTIPLE DIFFERENTIAL Byron Q. Jones, UnitedStates Army, Fort Knox, Ky.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 5 Claims.

The invention described herein may be manufactured and used by or for'the Government for governmental purposes, without the payment to me ofany royalty thereon.

This invention relates to differential gearing for automotive vehiclesand especially to a type adapted for vehicles having two or more drivewheels and a power source for each wheel.

It is an object of the invention to provide not only for the normaldifferential action at each Wheel but also provide for distribution ofpozker e distribution of power is unbroken if no two consecutive powersources are out of service. In the latter case one wheel will beisolated from the power. The transmission of power to adjacent wheels ismaintained in an unbroken chain by anl auxiliary shaft between the endwheels.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawing in which: e

Figure 1 is an axial sectional view of a two-unit gear housing, and

Figure 2 is a similar View showing a gear housing of-more than twounits.

Referring to the drawing by characters of reference, there is shown inFigure 1 drive shafts I and 2 with bevel gears 3 and 4 respectivelymeshing with ring gears 5 and 6. The ring gears carry planetary gears 'Iand 8 engaging respectively with sun gears 9, II and II), I2. A hollowshaft I3 is mounted so as to form a continuous unit between sun gears IIand I and the shaft carries a sprocket I4 which forms the connectionwith a vehicle wheel.

Sun gear I2 is fixed to a shaft I5 which carries a sprocket IS, andshaft I5 is connected to a shaft I'I and hence sun gear 9 through ashaft I8 running centrally back through the system.

When both shafts I and 2 are delivering power the action is normal andthe sun gears are al1 carried in unison by the planets to turn thevehicle wheels. For turning corners the differentials function in thenormal and well-known manner.

If, however, one of the motors is out of service the power from theremaining motor will be distributed to both wheels. For instance, assumethat the motor at shaft I is not running. In this case sun gear l0 willcarry gear I4 and sun gear I2 will carry sprocket I6. Conversely, if themotor at shaft 2 is out, sun gear II will carry sprocket I4 and sun gear9 will carry sprocket I6 through the intermediary of shaft I8.

As shown in Figure 2, the system is extended to include fourdifferential units and hence four wheel-driving sprockets.

It will be seen that each unit will function to carry the sprocket toits left if the latter is disabled as well asits own sprocket at itsright and all other operating units contribute to this result, sinceunder normal functioning the power distribution is unbroken throughoutther system.

The auxiliary shaft I9 closes the chain of distribution and functions t0operate sprocket 20 the same as if the latter were located to the leftof gear housing 2I. It is only when two adjacent power sources are outof service that the chain is broken, in which case one wheel drive willfail. Two drives will fail if three motors are out and so on. It issignificant to note that the end drives are, operatively, adjacent, andso one will always drive the other. For this reason an unbalanced driveWill not occur, for either both or neither of the end drives willfunction. If neither functions, the drive is still balanced as to thecentrally located units. In the absence of such things as shaft or gearfailures the vehicle will never be driven by a single wheel, two beingthe minimum.

It is to be noted that the construction of the instant device for massproduction is facilitated by the fact that most of the parts arestandard, such as the coupling between inner and outer shafts, thedifferential gear units, the gear housings and the sprockets.

I claim:

1. In a vehicle, a plurality of sources of power, a differential gearingSystem for each source, a shaft connecting units of the differentialsbetween adjacent systems and an auxiliary shaft forming a directconnection between the end units of the end systems.

2. In a vehicle, a plurality of sources of power, a differential gearingsystem for each source, a shaft connecting units of the differentialsbetween adjacent systems and an auxiliary shaft running axially of saidfirst mentioned shaft and connecting the end units of the end systems.

3. In a vehicle, a plurality of sources of power, a differential gearingsystem for each source comprising sun gears, a ring gear moved by thesource of power and carrying planetary gears to operate the sun gearsdifferentially, a shaft connecting sun gears between adjacent systemsand an auxiliary shaft forming a direct connection between the end unitsof the end systems.

fermement 4. In a vehicle, a plurality of sources of power, mentionedshaft and connecting the end units a differential gearing system foreach source of the end systems. comprising sun gears, a, ring gear movedby the 5. In a Vehicle as in claim 4, Wheel driving source of power andcarrying planetary gears to means on each of said rst mentioned shaftsand operate the sun gears diierentially, a shaft con- 5 on saidauxiliary shaft adjacent an end thereof. necting sun gears betweenadjacent systems and an auxiliary shaft running axially of said firstBYRON Q. JONES.

